Air pump



July 24, 1923. 1,463,109

' E. WITMAN AIR PUMP Filed Sept. 16. 1921 I ll lll lllll lllllll l llllllllllllfl INVENTOR 1 25 /9 jIv/zraim W'Zmniz WKg/QVLC y W76;

Patented July 24, 1923.

Unitas stares EPHRAIM WITMAN, OF SINKING SPRING, PENNSYLVANIA.

AIR PUMP.

Application filed September 16, 1921. Serial No. 501,013.

To all whom it may concern: I

Be it known that I, EPHRAIM WITMAN, a citizen of the United States, anda resident of Sinking Spring, in the county of Berks and State ofPennsylvania, have invented a new and Improved Air Pump, of which thefollowing is a description.

My invention relates to air pumps and while the invention is capable ofwider usefulness, it is more particularly intended for embodiment in atire pump.

The general object of the invention is to provide a pump that willefiiciently function as a double-acting pump to effect discharge of airwith each forward and return stroke of the piston.

A more specific object of the invention is to provide an embodiment ofthe invention respecting practical considerations with respect tostrength and simplicity as well as looking to convenience in assemblageor repair.

The nature of the invention and its distinctive features and advantageswill clearly appear as the description proceeds.

Reference is to be had to the accompanying drawings forming a part ofthis specification, it being understood that the drawings are merelyillustrative of one example of the invention.

Figure 1 is a vertical section of an air pump embodying my invention;

Figure 2 is a cross section on the line 2-2, Figure 1;

In carrying out my invention in accordance with the illustrated examplea cylinder 10 is provided in which a piston 11 operates, the plunger 12of the piston extending through the stuffing box 13 in the rear cylinderhead 10*, the numeral 1 1 indicating the gland of the stuffing box. Theplunger 12 is formed with a cross handle 15 or equivalent graspingmeans. The forward stroke of the piston may be limited by any suitabledevice, there being shown for the purpose a collar 12 thereon adapted tobe arrested by the gland 14:.

The discharge of the pump is advantage ously provided by a separate tube16 at the exterior of the cylinder 10, said tube having a nipple 17thereon for the attachment of a hose, a fragment of which is shown at18.

An L-shaped air-inlet port 19 is formed in the foot base 20 of the pumpto which base the flanged lower end of the cylinder 10 is secured as byscrewing into an upstanding neck or annular flange 20 At the exterior ofthe cylinder the port 19 may have'a guard cap 21 having lateral inletholes 22. The inner upturned end of the L-port 19 is provided with aninwardly opening valve 23 pivoted to the base 20 as at 2 1. An L-shapeddischarge port 25 is formed in the base 20 and like the inlet valve 19communicates at its inner end with the cylinder 10 in front of thepiston. The outer end of the port 25 communicates with the lower end ofthe discharge pipe 16. The discharge pipe 16 is formed in two separatedsections joined by a suitable coupling 17 or the like with which thenipple 17 advantageously is integral. Between the ends of the sectionsof the discharge pipe 16 a valve 26 is disposed, said valve beingpivoted at one end as at 27 within the nipple 17 in the illustrated example.

The upper and lower sides of the valve 26 are in convergent planes andthey are adapted to seat respectively on seats 28, 28 formed by theopposed ends of the sections of the discharge pipe 16.

A second air inlet port 29 is formed in the cylinder at the back of thepiston and preferably in the rear head 10 thereof, said port beingcontrolled by an inwardly opening valve 30 pivoted at one end as at 31to a fixed part of the cylinder 10. Communication between the cylinder10 at the back of the piston and the rear end of the discharge pipe 16may, as shown, he established by its lateral branch 33 tapped into theside of the cylinder near the rear head 1O as at 32.

In the operation of the pump a forward stroke of the piston 11 willinsure the closing of the valve 23, said valve having a tendency toclose by gravity and the air will be forced through discharge port 25and into the forward end of the discharge pipe 16, the pressure causingthe valve 26 to move against the upper valve seat 28 so that the airpasses to and through the nipple 17 to the hose 18. The forward movementof the piston 11 will have drawn air in through the rear inlet port 29,and upon the return stroke of the piston 11 the valve 30 will be closed,thereby causing the air at the back of the piston to be forced outthrough the branch passage 33 into the rear end of discharge pipe 16,the valve 26 at this time closing against the forward valve seat 28 sothat the air passes at the rear side of Valve 26, into the nipple 17 tothe'hose 18.

I would state in conclusion that While the illustrated exampleconstitutes a practical embodiment of my inventioml do not limit myselfstrictly to the exact details herein illustrated, since, manifestly thesame canbe' considerably varied Without departure from the spirit of theinvention as defined in the appended claim. a I Having thus described myinvention, I claim In an air pump of the class' described, a cylinder, abase and a cap for said cylinder, a-piston in said cylinder, an airintake open.

- ing in the cap and in the base, a hinged check valve for each of saidopenings disposed interiorly of said cylinder, said base having apassageway communicating the inner chamber of the cylinder With theoutside, said cylinder being formed With an opening adjacent its topend, a tube extending to said passageway, a second tube exetendingtosaid opening, a fitting having a nipple adapted to receive a rubber hoseconnecting said two tubes together adjacent the transverse and medialplane of the cylinder, anda hinged valve in said fitting adapted toalternately move in the front of said'tube in response to the movementof the piston.

'EPHRAIM WITMAN.

